Vehicular exhaust systems comprise one or more exhaust pipes extending from manifolds on the engine, one or more mufflers connected to the exhaust pipes and at least one tailpipe extending from the muffler. Vehicles may also include antipollution devices, such as catalytic converters, incorporated into the exhaust system. The exhaust system may circuitously extend 10 to 20 feet from the engine to the rear end of the vehicle. On certain trucks, the exhaust system may extend even further.
The various components of the exhaust system are suspended from the underside of the vehicle. In the past, this mounting of the exhaust system has been accomplished with metallic bracket assemblies which typically would include bolts, nuts and a variety of support members. Recently, however, some vehicular manufacturers have been utilizing rubber insulators into which metallic studs are mounted. The insulators are solid rubber members that typically are between one inch and one and five-eights inches thick. Each insulator usually will include two generally circular apertures extending entirely therethrough for receiving two studs.
Each stud is a generally cylindrical metallic member that may be bent into an appropriate configuration for mounting on a particular vehicle. The cylindrical body of the stud has a diameter substantially equal to the diameter of the apertures extending through the insulator. The stud also includes an enlarged head. The juncture between the head and the cylindrical body defines a shoulder which extends outwardly and generally perpendicular to the outer cylindrical surface of the stud body. The extreme end of the head generally perferably is tapered down to a dimension that is equal to or smaller than the diameter of the apertures through the insulator.
In use, the tapered head is forced entirely through an aperture in the insulator. This can be accomplished fairly easily because the tapered configuration of the head causes the insulator to deform as the stud is pushed therethrough. However, once the enlarged head of the stud emerges from the opposite side of the insulator, the entire insulator will return to its initial shape with the diameter of the aperture in the insulator substantially conforming to the diameter of the stud body. The outwardly extending shoulder of the enlarge head adjacent to the stud body will be significantly larger than the aperture in the insulator. Thus, the stud cannot easily become disengaged from the insulator.
One of the studs inserted in an insulator, as explained above, is attached to an appropriate supporting structure on the vehicle. Another similar stud inserted in the insulator is attached to an appropriate part of the vehicular exhaust system. Thus, the combination of studs and rubber insulator are utilized to hold the exhaust system to the vehicle. This combination is believed to be less expensive than many prior art metallic mounting structures, is not susceptible to rusting, is inexpensive and may function to dampen certain exhaust system vibrations from the vehicular body.
Despite the apparent advantages of mounting exhaust systems with rubber insulators, and despite the wide spread acceptance of rubber insulators, it has now been found that these insulators make repairs and replacements to the vehicular exhaust system very difficult. Specifically, the enlarged head cannot readily be removed from the rubber insulator. This difficulty is caused by the outwardly extending shoulder at the juncture between the enlarged head and the body of the stud. This outwardly extending shoulder is not tapered like the opposed side of the head. Therefore the shoulder edge of the enlarged head cannot readily make its initial entry into the apertures in the insulator to cause a gradual expansion of the insulator adjacent thereto.
Vehicular maintanance personnel have resorted to several largely undesirable techniques for a replacing exhaust systems mounted with the above described rubber insulators and metallic studs. One common approach has involved cutting the metallic stud intermediate the insulator and the exhaust system component to which the stud is mounted. This approach generally takes an inordinate amount of time and requires the use of cutting tools in rather closely confined spaces. Furthermore, this approach often requires the rewelding of the stud to the vehicular body. This rewelding in close proximity to other parts of the vehicle can be damaging to the vehicle and dangerous to the worker.
Other vehicle maintenance personnel have attempted to use knives, razors or the like to cut the insulator from the stud. This approach also can be quite dangerous due to the use of a sharp instrument on a very tough resilient object in a closely confined space. Furthermore, even if this approach is successful, it results in the destruction of a functional insulator.
Still other workers attempt to remove the stud from the insulator by using screwdrivers, chisles, hammers and the like to forcibly urge the stud through the aperture in the insulator. Again, these attempts are time consuming, awkward and potentially dangerous.
Several hand tools have been developed for mounting one member to another or for removing a member from another. None of these known tools, however, would be at all helpful in removing a stud from an insulator as described above. For example, U.S. Pat. No. 3,823,462 which issued to Kanda on July 16, 1974 shows a hand tool for removing a broken component from a sprinkler system. The tool shown in U.S. Pat. No. 3,823,462 shows a first tool portion circumferentially engaging the outer surface of a first part of the sprinkler system and a second tool portion for pulling the broken part of the system therefrom.
U.S. Pat. No. 4,170,125 which issued to Minka on Oct. 9, 1979 shows a plier-like tool for crimping ferrules onto conduits.
U.S. Pat. No. 3,017,692 which issued to Burnell on Jan. 23, 1962 shows another plier-like tool for circumferentially surrounding a cylindrical spring clip to close that clip around a pin or post.
U.S. Pat. No. 1,316,409 issued to Bahre on Sept. 16, 1919 and shows another simple plier-like tool for extracting cotter pins. A very similar tool is shown in U.S. Pat. No. 1,326,858 which issued to Glasscock on Dec. 30, 1919.
Still other hand tools similar to those decribed above are shown in U.S. Pat. No. 851,794 which issued to Bernard on Apr. 30, 1907; U.S. Pat. No. 827,392 which issued to Prangemeier on July 31, 1906; U.S. Pat. No. 2,700,910 which issued to Van Niel on Feb. 1, 1955; U.S. Pat. No. 2,952,173 which issued to Fexas on Sept. 13, 1960; U.S. Pat. No. 3,924,507 which issued to Faroni on Dec. 9, 1975; U.S. Pat. No. 3,991,635 which issued to Marone on Nov. 16, 1976; U.S. Pat. No. 4,179,782 which issued to Forman et al on Dec. 25, 1979; U.S. Pat. No. 4,222,985 which issued to Greenleaf on Dec. 16, 1980; and British Pat. No. 1,293,158 which issued to Murphy et al on Oct. 18, 1972.
As noted above, none of these known tools suggest any way to remove the above described stud having an enlarged head from the rubber insulator described above.
In view of the above, it is an object of the subject invention to provide a tool for removing a mounting stud from an insulator of a vehicular exhaust system.
It is another object of the subject invention to provide a tool that can be easily and efficiently used on insulators of any of a variety of configurations.
It is a further object of the subject invention to provide a tool for removing mounting studs from insulators that does not require the use of other tools simultaneously.
Is an additional object of the subject invention to provide a tool for removing mounting studs from insulators that is safe to use.